Expression of HD-ZIP genes and AUX/IAA genes.
Transcript abundance of the HD-ZIP genes
AtHB8 (A), AtHB9 (B), AtHB14 (C),
IFL1/REV (D), and AtHB20 (E) and of
the AUX/IAA genes IAA1 (F) and
IAA19 (G) were determined by northern-blot hybridization to
total RNA from wild type (wt), mp
mutant, and 35S::MP plants exposed for
30 min to 0, 10, and 100 μm IAA (indicated on
x axes, genotypes below). Transcript levels (y
axes) for each gene were calculated as multiples of the wild-type level
at 0 μm IAA. Columns represent the mean ±
se from 3 to 5 (A–D), and
the results of two experiments (F and G). Significance of
genotype-dependent differences between mp and
35S::MP values relative to
wt type values under identical conditions as determined by
Student's t test analysis is indicated by asterisks (*,
0.01 ≤ P < 0.05; **, 0.001 ≤
P < 0.01; ***, P < 0.001). Note that
the absolute induction levels of IAA1 and IAA19 appear extremely high
because of extremely low expression at 0 μm
IAA.